Rails jQuery adapter

rails.js

(function($, undefined) {

/**
 * Unobtrusive scripting adapter for jQuery
 * https://github.com/rails/jquery-ujs
 *
 * Requires jQuery 1.8.0 or later.
 *
 * Released under the MIT license
 *
 */

  $.ajaxSettings.dataType = "script";

  // Cut down on the number of issues from people inadvertently including jquery_ujs twice
  // by detecting and raising an error when it happens.
  if ( $.rails !== undefined ) {
    $.error('jquery-ujs has already been loaded!');
  }

  // Shorthand to make it a little easier to call public rails functions from within rails.js
  var rails;
  var $document = $(document);

  $.rails = rails = {
    // Link elements bound by jquery-ujs
    linkClickSelector: 'a[data-confirm], a[data-method], a[data-remote], a[data-disable-with], a[data-disable]',

    // Button elements bound by jquery-ujs
    buttonClickSelector: 'button[data-remote]:not(form button), button[data-confirm]:not(form button)',

    // Select elements bound by jquery-ujs
    inputChangeSelector: 'select[data-remote], input[data-remote], textarea[data-remote]',

    // Form elements bound by jquery-ujs
    formSubmitSelector: 'form',

    // Form input elements bound by jquery-ujs
    formInputClickSelector: 'form input[type=submit], form input[type=image], form button[type=submit], form button:not([type]), input[type=submit][form], input[type=image][form], button[type=submit][form], button[form]:not([type])',

    // Form input elements disabled during form submission
    disableSelector: 'input[data-disable-with]:enabled, button[data-disable-with]:enabled, textarea[data-disable-with]:enabled, input[data-disable]:enabled, button[data-disable]:enabled, textarea[data-disable]:enabled',

    // Form input elements re-enabled after form submission
    enableSelector: 'input[data-disable-with]:disabled, button[data-disable-with]:disabled, textarea[data-disable-with]:disabled, input[data-disable]:disabled, button[data-disable]:disabled, textarea[data-disable]:disabled',

    // Form required input elements
    requiredInputSelector: 'input[name][required]:not([disabled]),textarea[name][required]:not([disabled])',

    // Form file input elements
    fileInputSelector: 'input[type=file]',

    // Link onClick disable selector with possible reenable after remote submission
    linkDisableSelector: 'a[data-disable-with], a[data-disable]',

    // Button onClick disable selector with possible reenable after remote submission
    buttonDisableSelector: 'button[data-remote][data-disable-with], button[data-remote][data-disable]',

    // Make sure that every Ajax request sends the CSRF token
    CSRFProtection: function(xhr) {
      var token = $('meta[name="csrf-token"]').attr('content');
      if (token) xhr.setRequestHeader('X-CSRF-Token', token);
    },

    // making sure that all forms have actual up-to-date token(cached forms contain old one)
    refreshCSRFTokens: function(){
      var csrfToken = $('meta[name=csrf-token]').attr('content');
      var csrfParam = $('meta[name=csrf-param]').attr('content');
      $('form input[name="' + csrfParam + '"]').val(csrfToken);
    },

    // Triggers an event on an element and returns false if the event result is false
    fire: function(obj, name, data) {
      var event = $.Event(name);
      obj.trigger(event, data);
      return event.result !== false;
    },

    // Default confirm dialog, may be overridden with custom confirm dialog in $.rails.confirm
    confirm: function(message) {
      return confirm(message);
    },

    // Default ajax function, may be overridden with custom function in $.rails.ajax
    ajax: function(options) {
      return $.ajax(options);
    },

    // Default way to get an element's href. May be overridden at $.rails.href.
    href: function(element) {
      return element.attr('href');
    },

    // Submits "remote" forms and links with ajax
    handleRemote: function(element) {
      var method, url, data, elCrossDomain, crossDomain, withCredentials, dataType, options;

      if (rails.fire(element, 'ajax:before')) {
        elCrossDomain = element.data('cross-domain');
        crossDomain = elCrossDomain === undefined ? null : elCrossDomain;
        withCredentials = element.data('with-credentials') || null;
        dataType = element.data('type') || ($.ajaxSettings && $.ajaxSettings.dataType);

        if (element.is('form')) {
          method = element.attr('method');
          url = element.attr('action');
          data = element.serializeArray();
          // memoized value from clicked submit button
          var button = element.data('ujs:submit-button');
          if (button) {
            data.push(button);
            element.data('ujs:submit-button', null);
          }
        } else if (element.is(rails.inputChangeSelector)) {
          method = element.data('method');
          url = element.data('url');
          data = element.serialize();
          if (element.data('params')) data = data + "&" + element.data('params');
        } else if (element.is(rails.buttonClickSelector)) {
          method = element.data('method') || 'get';
          url = element.data('url');
          data = element.serialize();
          if (element.data('params')) data = data + "&" + element.data('params');
        } else {
          method = element.data('method');
          url = rails.href(element);
          data = element.data('params') || null;
        }

        options = {
          type: method || 'GET', data: data, dataType: dataType,
          // stopping the "ajax:beforeSend" event will cancel the ajax request
          beforeSend: function(xhr, settings) {
            if (settings.dataType === undefined) {
              xhr.setRequestHeader('accept', '*/*;q=0.5, ' + settings.accepts.script);
            }
            if (rails.fire(element, 'ajax:beforeSend', [xhr, settings])) {
              element.trigger('ajax:send', xhr);
            } else {
              return false;
            }
          },
          success: function(data, status, xhr) {
            element.trigger('ajax:success', [data, status, xhr]);
          },
          complete: function(xhr, status) {
            element.trigger('ajax:complete', [xhr, status]);
          },
          error: function(xhr, status, error) {
            element.trigger('ajax:error', [xhr, status, error]);
          },
          crossDomain: crossDomain
        };

        // There is no withCredentials for IE6-8 when
        // "Enable native XMLHTTP support" is disabled
        if (withCredentials) {
          options.xhrFields = {
            withCredentials: withCredentials
          };
        }

        // Only pass url to `ajax` options if not blank
        if (url) { options.url = url; }

        return rails.ajax(options);
      } else {
        return false;
      }
    },

    // Handles "data-method" on links such as:
    // <a href="/users/5" data-method="delete" rel="nofollow" data-confirm="Are you sure?">Delete</a>
    handleMethod: function(link) {
      var href = rails.href(link),
        method = link.data('method'),
        target = link.attr('target'),
        csrfToken = $('meta[name=csrf-token]').attr('content'),
        csrfParam = $('meta[name=csrf-param]').attr('content'),
        form = $('<form method="post" action="' + href + '"></form>'),
        metadataInput = '<input name="_method" value="' + method + '" type="hidden" />';

      if (csrfParam !== undefined && csrfToken !== undefined) {
        metadataInput += '<input name="' + csrfParam + '" value="' + csrfToken + '" type="hidden" />';
      }

      if (target) { form.attr('target', target); }

      form.hide().append(metadataInput).appendTo('body');
      form.submit();
    },

    // Helper function that returns form elements that match the specified CSS selector
    // If form is actually a "form" element this will return associated elements outside the from that have
    // the html form attribute set
    formElements: function(form, selector) {
      return form.is('form') ? $(form[0].elements).filter(selector) : form.find(selector);
    },

    /* Disables form elements:
      - Caches element value in 'ujs:enable-with' data store
      - Replaces element text with value of 'data-disable-with' attribute
      - Sets disabled property to true
    */
    disableFormElements: function(form) {
      rails.formElements(form, rails.disableSelector).each(function() {
        rails.disableFormElement($(this));
      });
    },

    disableFormElement: function(element) {
      var method, replacement;

      method = element.is('button') ? 'html' : 'val';
      replacement = element.data('disable-with');

      element.data('ujs:enable-with', element[method]());
      if (replacement !== undefined) {
        element[method](replacement);
      }

      element.prop('disabled', true);
    },

    /* Re-enables disabled form elements:
      - Replaces element text with cached value from 'ujs:enable-with' data store (created in `disableFormElements`)
      - Sets disabled property to false
    */
    enableFormElements: function(form) {
      rails.formElements(form, rails.enableSelector).each(function() {
        rails.enableFormElement($(this));
      });
    },

    enableFormElement: function(element) {
      var method = element.is('button') ? 'html' : 'val';
      if (element.data('ujs:enable-with')) element[method](element.data('ujs:enable-with'));
      element.prop('disabled', false);
    },

   /* For 'data-confirm' attribute:
      - Fires `confirm` event
      - Shows the confirmation dialog
      - Fires the `confirm:complete` event

      Returns `true` if no function stops the chain and user chose yes; `false` otherwise.
      Attaching a handler to the element's `confirm` event that returns a `falsy` value cancels the confirmation dialog.
      Attaching a handler to the element's `confirm:complete` event that returns a `falsy` value makes this function
      return false. The `confirm:complete` event is fired whether or not the user answered true or false to the dialog.
   */
    allowAction: function(element) {
      var message = element.data('confirm'),
          answer = false, callback;
      if (!message) { return true; }

      if (rails.fire(element, 'confirm')) {
        answer = rails.confirm(message);
        callback = rails.fire(element, 'confirm:complete', [answer]);
      }
      return answer && callback;
    },

    // Helper function which checks for blank inputs in a form that match the specified CSS selector
    blankInputs: function(form, specifiedSelector, nonBlank) {
      var inputs = $(), input, valueToCheck,
          selector = specifiedSelector || 'input,textarea',
          allInputs = form.find(selector);

      allInputs.each(function() {
        input = $(this);
        valueToCheck = input.is('input[type=checkbox],input[type=radio]') ? input.is(':checked') : input.val();
        // If nonBlank and valueToCheck are both truthy, or nonBlank and valueToCheck are both falsey
        if (!valueToCheck === !nonBlank) {

          // Don't count unchecked required radio if other radio with same name is checked
          if (input.is('input[type=radio]') && allInputs.filter('input[type=radio]:checked[name="' + input.attr('name') + '"]').length) {
            return true; // Skip to next input
          }

          inputs = inputs.add(input);
        }
      });
      return inputs.length ? inputs : false;
    },

    // Helper function which checks for non-blank inputs in a form that match the specified CSS selector
    nonBlankInputs: function(form, specifiedSelector) {
      return rails.blankInputs(form, specifiedSelector, true); // true specifies nonBlank
    },

    // Helper function, needed to provide consistent behavior in IE
    stopEverything: function(e) {
      $(e.target).trigger('ujs:everythingStopped');
      e.stopImmediatePropagation();
      return false;
    },

    //  replace element's html with the 'data-disable-with' after storing original html
    //  and prevent clicking on it
    disableElement: function(element) {
      var replacement = element.data('disable-with');

      element.data('ujs:enable-with', element.html()); // store enabled state
      if (replacement !== undefined) {
        element.html(replacement);
      }

      element.bind('click.railsDisable', function(e) { // prevent further clicking
        return rails.stopEverything(e);
      });
    },

    // restore element to its original state which was disabled by 'disableElement' above
    enableElement: function(element) {
      if (element.data('ujs:enable-with') !== undefined) {
        element.html(element.data('ujs:enable-with')); // set to old enabled state
        element.removeData('ujs:enable-with'); // clean up cache
      }
      element.unbind('click.railsDisable'); // enable element
    }
  };

  if (rails.fire($document, 'rails:attachBindings')) {

    $.ajaxPrefilter(function(options, originalOptions, xhr){ if ( !options.crossDomain ) { rails.CSRFProtection(xhr); }});

    // This event works the same as the load event, except that it fires every
    // time the page is loaded.
    //
    // See https://github.com/rails/jquery-ujs/issues/357
    // See https://developer.mozilla.org/en-US/docs/Using_Firefox_1.5_caching
    $(window).on("pageshow.rails", function () {
      $($.rails.enableSelector).each(function () {
        var element = $(this);

        if (element.data("ujs:enable-with")) {
          $.rails.enableFormElement(element);
        }
      });

      $($.rails.linkDisableSelector).each(function () {
        var element = $(this);

        if (element.data("ujs:enable-with")) {
          $.rails.enableElement(element);
        }
      });
    });

    $document.delegate(rails.linkDisableSelector, 'ajax:complete', function() {
        rails.enableElement($(this));
    });

    $document.delegate(rails.buttonDisableSelector, 'ajax:complete', function() {
        rails.enableFormElement($(this));
    });

    $document.delegate(rails.linkClickSelector, 'click.rails', function(e) {
      var link = $(this), method = link.data('method'), data = link.data('params'), metaClick = e.metaKey || e.ctrlKey;
      if (!rails.allowAction(link)) return rails.stopEverything(e);

      if (!metaClick && link.is(rails.linkDisableSelector)) rails.disableElement(link);

      if (link.data('remote') !== undefined) {
        if (metaClick && (!method || method === 'GET') && !data) { return true; }

        var handleRemote = rails.handleRemote(link);
        // response from rails.handleRemote() will either be false or a deferred object promise.
        if (handleRemote === false) {
          rails.enableElement(link);
        } else {
          handleRemote.fail( function() { rails.enableElement(link); } );
        }
        return false;

      } else if (method) {
        rails.handleMethod(link);
        return false;
      }
    });

    $document.delegate(rails.buttonClickSelector, 'click.rails', function(e) {
      var button = $(this);

      if (!rails.allowAction(button)) return rails.stopEverything(e);

      if (button.is(rails.buttonDisableSelector)) rails.disableFormElement(button);

      var handleRemote = rails.handleRemote(button);
      // response from rails.handleRemote() will either be false or a deferred object promise.
      if (handleRemote === false) {
        rails.enableFormElement(button);
      } else {
        handleRemote.fail( function() { rails.enableFormElement(button); } );
      }
      return false;
    });

    $document.delegate(rails.inputChangeSelector, 'change.rails', function(e) {
      var link = $(this);
      if (!rails.allowAction(link)) return rails.stopEverything(e);

      rails.handleRemote(link);
      return false;
    });

    $document.delegate(rails.formSubmitSelector, 'submit.rails', function(e) {
      var form = $(this),
        remote = form.data('remote') !== undefined,
        blankRequiredInputs,
        nonBlankFileInputs;

      if (!rails.allowAction(form)) return rails.stopEverything(e);

      // skip other logic when required values are missing or file upload is present
      if (form.attr('novalidate') == undefined) {
        blankRequiredInputs = rails.blankInputs(form, rails.requiredInputSelector);
        if (blankRequiredInputs && rails.fire(form, 'ajax:aborted:required', [blankRequiredInputs])) {
          return rails.stopEverything(e);
        }
      }

      if (remote) {
        nonBlankFileInputs = rails.nonBlankInputs(form, rails.fileInputSelector);
        if (nonBlankFileInputs) {
          // slight timeout so that the submit button gets properly serialized
          // (make it easy for event handler to serialize form without disabled values)
          setTimeout(function(){ rails.disableFormElements(form); }, 13);
          var aborted = rails.fire(form, 'ajax:aborted:file', [nonBlankFileInputs]);

          // re-enable form elements if event bindings return false (canceling normal form submission)
          if (!aborted) { setTimeout(function(){ rails.enableFormElements(form); }, 13); }

          return aborted;
        }

        rails.handleRemote(form);
        return false;

      } else {
        // slight timeout so that the submit button gets properly serialized
        setTimeout(function(){ rails.disableFormElements(form); }, 13);
      }
    });

    $document.delegate(rails.formInputClickSelector, 'click.rails', function(event) {
      var button = $(this);

      if (!rails.allowAction(button)) return rails.stopEverything(event);

      // register the pressed submit button
      var name = button.attr('name'),
        data = name ? {name:name, value:button.val()} : null;

      button.closest('form').data('ujs:submit-button', data);
    });

    $document.delegate(rails.formSubmitSelector, 'ajax:send.rails', function(event) {
      if (this == event.target) rails.disableFormElements($(this));
    });

    $document.delegate(rails.formSubmitSelector, 'ajax:complete.rails', function(event) {
      if (this == event.target) rails.enableFormElements($(this));
    });

    $(function(){
      rails.refreshCSRFTokens();
    });
  }

})( jQuery );